x86: fix switch_to() clobbers
Liu Pingfan noticed that switch_to() clobbers more registers than its
asm constraints specify.
We get away with this due to luck mostly - schedule()
by its nature only has 'local' state which gets reloaded
automatically. Fix it nevertheless, we could hit this anytime.
it turns out that with the extra constraints gcc manages to make
schedule() even more compact:
text data bss dec hex filename
28626 684 2640 31950 7cce sched.o.before
28613 684 2640 31937 7cc1 sched.o.after
Reported-by: Liu Pingfan <kernelfans@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed